The subject matter disclosed herein relates to a sensing device attached to a target object using a bonding material.
Several industries (e.g., oil and gas, refinery, chemical, power generation) require the transport of fluid (e.g., liquids or gases) through pipes. Nondestructive testing systems can be placed on the outer surface of these pipes to monitor corrosion/erosion of the pipes, including corrosion/erosion on the interior of pipe walls. In some nondestructive testing systems, the probe or other nondestructive testing device is permanently coupled to the outer surface of the pipe to continuously monitor corrosion/erosion at that location to determine pipe corrosion/erosion rates and to determine whether that pipe location is in need of preventative maintenance to prevent a pipe failure.
One example of a nondestructive testing system used to monitor corrosion/erosion of a pipe is an ultrasonic testing system. When conducting ultrasonic testing of a pipe, an ultrasonic pulse is emitted from a probe coupled to the outer surface of the pipe and passed through the pipe. As the ultrasonic pulse passes into and through the pipe, various pulse reflections called echoes are reflected back to the probe as the pulse interacts with the outer surface of the pipe, internal structures, voids or occlusions within the pipe, and with the inner surface (or back wall) of the pipe. The echo signals can be displayed on a screen with echo amplitudes appearing as vertical traces and time of flight or distance as horizontal traces. By tracking the time difference between the transmission of the ultrasonic pulse and the receipt of the echoes, various characteristics of the pipe can be determined, including pipe thickness. If the thickness of the pipe at the location of the ultrasonic testing system decreases over time (e.g., as would be shown be a reduction in the time of flight of the back wall echo), this can be an indication of corrosion/erosion.
In an ultrasonic testing system, the substrate of a piezoelectric sensing device is attached to the outer surface of a pipe using a bonding material. The bonding material provides mechanical adhesion and forms a thin bond line between the piezoelectric sensing device and the pipe. Once cured, the bonding material holds the substrate to the pipe. In some installations, when the piezoelectric sensing device is attached to the pipe, the bond line formed by the bonding material is too thick, degrading the performance of the piezoelectric sensing device. The bond to the pipe formed by the bonding material, or the lamination between the layers of the substrate, are subject to failure, especially when the piezoelectric sensing device is inadvertently contacted from the side, causing the substrate to peel off of the pipe or a laminated layer to peel off of the substrate.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.